In the current process for manufacturing aluminum electrolytic capacitors, the anodes are typically punched or stamped from a sheet of material using a mechanical die. After the anodes are punched or stamped, the anodes are assembled into stacks with cathodes. Separators are positioned between cathodes and anodes that are adjacent to one another in the stack. The punching process can cause the edges of the anode to have burrs and other particles that can penetrate the separator and cause a short in the capacitor or otherwise compromise the quality and life of the capacitor.
Additionally, the physical stress of the punching or stamping process can cause cracking of the anode. Tabs are often welded to the anodes to provide electrical communication between the anodes and a terminal of the capacitor. The cracks formed by stamping or punching can propagate when welding the tabs to the anodes. Propagation of the cracks can cause the tabs to detach from the anode.
Further, the dies are made of steel and can contaminate the anode with iron particles. In addition to the iron penetrating the separator, the iron is also a source of corrosion that can lead to leakage and premature capacitor failure.
For the above reasons, there is a need for improved capacitor anodes.